Yes, there is a fort here—a National Historic Landmark built in the mid-1800s to protect the country’s southernmost coastline—but locals know it for its excellent beach. A nice sandy expanse is a rarity in the Florida Keys; they’re surrounded by coral reefs, which make for primo fishing and diving but block the waves that are needed to produce a proper beach. But here, sand is trucked in to create a close facsimile—plus the water is wonderfully clear and calm, and there’s great snorkeling thanks to an offshore reef.